Dyes as Corrosion Inhibitors for Aluminium Alloys in Acid Media Part-3. Triphenylmethane Dyes as Inhibitors for Aluminium-Copper Alloy in Sulphuric Acid
| Main Authors: | J D. TALATI, J. M. DARAJI |
|---|---|
| Format: | Article Journal |
| Bahasa: | eng |
| Terbitan: |
, 1988
|
| Subjects: | |
| Online Access: |
https://zenodo.org/record/6024232 |
Daftar Isi:
- Chemistry Department, Shri U. P. Arts, Smt. M. G. Panchal Science and Shri V. L. Shah Commerce College, Pilvai-382 850 Manuscript received 7 April 1986, revised 4 September 1987, accepted 16 December 1987 The corrosion of Al-4% Cu alloy in sulphuric acid increases with acid concentration and immersion period, the plots of ζ(weight loss) vs C (concn ) being parabolic in nature following the equation, C=kζn , where n=4.4 and ζ=6 6 x 10—'. At constant acid concentration, the inhibitive efficiency of the triphenylmethane dyes increases with inhibitor concentration whereas at constant inhibitor concentration the efficiency first decreases with the increase in acid concentration upto 1.0 Al and then decreases ; the increase in efficiency in 4 M acid being in the order, methyl violet < fuchsine base < victoria blue < fuchsine acid < light green < crystal violet < malachite green < fast green. The B26S aluminium alloy in 0.25 M H,S0, develops a corrosion potential of — 755 mV vs SCE and the potential remains unaffected on addition of inhibitors. Galvanostatic polarisation curves show polarisation of both, the cathodes as well as the anodes. The inhibitors appear to function through general adsorption following Langmuir adsorption isotherm.